U.S. patent number 9,862,900 [Application Number 14/421,793] was granted by the patent office on 2018-01-09 for device and method for introducing oxygen into a pressurized fluidized-bed gasification process.
This patent grant is currently assigned to THYSSENKRUPP INDUSTRIAL SOLUTIONS AG. The grantee listed for this patent is THYSSENKRUPP INDUSTRIAL SOLUTIONS AG. Invention is credited to Ralf Abraham, Simon Boris Hafner, Domenico Pavone, Reinald Schulze Eckel, Dobrin Toporov.
United States Patent |
9,862,900 |
Abraham , et al. |
January 9, 2018 |
Device and method for introducing oxygen into a pressurized
fluidized-bed gasification process
Abstract
The invention relates to an oxygen lance that has at least three
mutually coaxial pipes, each of which delimits at least one annular
gap. The outermost pipe is designed to conduct superheated steam
and has a steam supply point, the central pipe is designed as an
annular gap, and the innermost pipe is designed to conduct oxygen
at a temperature of no higher than 180.degree. C. and has an oxygen
supply point. A temperature sensor is arranged within the innermost
pipe, said temperature sensor extending to just in front of the
opening of the innermost pipe. The innermost pipe tapers in the
form of a nozzle before opening; the innermost pipe opens into the
central pipe; and the opening of the central pipe protrudes farther
relative to the opening of the outermost pipe.
Inventors: |
Abraham; Ralf (Bergkamen,
DE), Pavone; Domenico (Bochum, DE), Schulze
Eckel; Reinald (Munster, DE), Toporov; Dobrin
(Dortmund, DE), Hafner; Simon Boris (Dortmund,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
THYSSENKRUPP INDUSTRIAL SOLUTIONS AG |
Essen |
N/A |
DE |
|
|
Assignee: |
THYSSENKRUPP INDUSTRIAL SOLUTIONS
AG (Essen, DE)
|
Family
ID: |
49036545 |
Appl.
No.: |
14/421,793 |
Filed: |
August 8, 2013 |
PCT
Filed: |
August 08, 2013 |
PCT No.: |
PCT/EP2013/002369 |
371(c)(1),(2),(4) Date: |
February 13, 2015 |
PCT
Pub. No.: |
WO2014/026748 |
PCT
Pub. Date: |
February 20, 2014 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20150232770 A1 |
Aug 20, 2015 |
|
Foreign Application Priority Data
|
|
|
|
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Aug 14, 2012 [DE] |
|
|
10 2012 016 086 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F27B
15/10 (20130101); C10J 3/56 (20130101); C10J
3/54 (20130101); F27D 3/16 (20130101); C21B
7/163 (20130101); C10J 3/78 (20130101); C21C
5/4673 (20130101); C21C 5/4606 (20130101); C10J
3/503 (20130101); C21C 5/5217 (20130101); C10J
2200/152 (20130101); C10J 2300/0959 (20130101); Y02P
10/20 (20151101); C10J 2300/1846 (20130101) |
Current International
Class: |
C10J
3/54 (20060101); C10J 3/56 (20060101); C10J
3/78 (20060101); C21C 5/46 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2801784 |
|
Aug 2006 |
|
CN |
|
3439404 |
|
Oct 1986 |
|
DE |
|
4407651 |
|
Oct 1995 |
|
DE |
|
2476956 |
|
Jul 2012 |
|
EP |
|
820820 |
|
Sep 1959 |
|
GB |
|
1001032 |
|
Aug 1965 |
|
GB |
|
2106413 |
|
Mar 1998 |
|
RU |
|
2301837 |
|
Jun 2005 |
|
RU |
|
01/75367 |
|
Oct 2001 |
|
WO |
|
2010/006723 |
|
Jan 2010 |
|
WO |
|
Other References
German Language International Search Report for International
patent application No. PCT/EP2013/002369; dated Oct. 24, 2013.
cited by applicant .
English Translation of International Search Report for
International patent application No. PCT/EP2013/002369; dated Oct.
24, 2013. cited by applicant .
English translation of the abstract for DE 3439404 (C2). cited by
applicant .
English translation of the abstract for DE 4407651 (C1). cited by
applicant .
English language Abstract of CN 2801784 Y listed above. cited by
applicant.
|
Primary Examiner: Chandler; Kaity
Attorney, Agent or Firm: thyssenkrupp North America,
Inc.
Claims
The invention claimed is:
1. An oxygen lance comprising: an inner pipe including an inlet
disposed at a proximal end thereof, a mouth disposed at a distal
end thereof, and a tapered nozzle section disposed upstream of said
mouth; a middle pipe coaxially disposed around an outer surface of
at least said distal end of said inner pipe and defining a middle
annular gap between the outer surface of said inner pipe and an
inner surface of said middle pipe, said middle pipe having a mouth
disposed at a distal end thereof; an outer pipe coaxially disposed
around an outer surface of at least a portion of said middle pipe
and defining an outer annular gap between the outer surface of said
middle pipe and an inner surface of said outer pipe, said outer
pipe having an inlet disposed at a proximal end thereof and a mouth
disposed at a distal end of said outer pipe beyond which said mouth
of said middle pipe extends, wherein the outer pipe extends
distally beyond a location within the middle pipe where the mouth
of the inner pipe terminates; and a temperature probe disposed
inside said inner pipe and having a distal end disposed upstream of
said mouth of said inner pipe at said distal end thereof, wherein
the temperature probe extends along a longitudinal axis of the
inner pipe.
2. The oxygen lance of claim 1, wherein said mouth of said middle
pipe is open.
3. The oxygen lance of claim 1, wherein said middle pipe includes a
feed inlet and is configured to permit dry gas to flow through said
middle pipe.
4. The oxygen lance of claim 3, wherein said middle pipe has a
tapered nozzle section disposed upstream of said mouth of said
inner pipe.
5. The oxygen lance of claim 1 wherein the inlet of the inner pipe
is an inlet, wherein the inner pipe is configured to permit oxygen
having a maximum temperature of 180.degree. C. to flow there
through from the inlet to the mouth, wherein the middle pipe is
configured to permit oxygen to flow out of the mouth of the inner
pipe and into the middle pipe, wherein the inlet of the outer pipe
is a steam feed inlet, wherein the outer pipe is configured to
permit superheated steam to flow through the outer pipe.
6. The oxygen lance of claim 1 wherein the temperature probe
measures a temperature of a substance flowing through the inner
pipe.
7. The oxygen lance of claim 1 wherein the middle pipe has a
constant diameter at the location where the mount of the inner pipe
terminates.
8. The oxygen lance of claim 1 further comprising a regulating
valve disposed upstream of the inlet of the inner pipe for
regulating an amount of gas or stopping gas from being fed into the
inner pipe based on measurements from the temperature probe.
9. The oxygen lance of claim 1 wherein the mouth of the middle pipe
that extends beyond the mouth of the outer pipe has a constant
diameter.
10. A method for introducing oxygen into a fluidized bed
gasification reactor operated according to the HTW method,
comprising: providing an oxygen lance according to claim 1; feeding
moist gas into the outer pipe at a pressure above a pressure in the
fluidized bed gasification reactor; feeding oxygen into the inner
pipe at a temperature of up to 180.degree. C. and a pressure above
a pressure in the fluidized bed gasification reactor; expelling the
oxygen from the mouth of the inner pipe into the middle pipe;
expelling an emerging free jet of gas from the mouth of the middle
pipe, the emerging free jet of gas including at least the oxygen
expelled from the inner pipe into the middle pipe; expelling moist
gas from the mouth of the outer pipe as a cladding flow surrounding
the mouth of the middle pipe and the associated emerging free jet
of gas expelled therefrom, wherein a flow velocity of the emerging
moist gas is higher than a flow velocity of oxygen expelled from
the inner pipe.
11. The method of claim 10, further comprising: feeding dry gas
into the middle pipe; mixing, in the middle pipe, the oxygen
expelled from the inner pipe with the dry gas in the middle pipe,
upstream of the mouth of the middle pipe, wherein said expelled
emerging free jet of gas from said middle pipe is the mixed oxygen
and dry gas; and expelling moist gas from the mouth of the outer
pipe as a cladding flow surrounding the mouth of the middle pipe
and the associated emerging free jet of gas expelled therefrom,
wherein a flow velocity of the emerging moist gas is higher than a
flow velocity of the mixed oxygen and dry gas expelled from the
middle pipe.
12. The method of claim 10, wherein the moist gas is superheated
steam.
13. The method of claim 10, wherein the moist gas is a mixture of
carbon dioxide and superheated steam.
14. The method of claim 10, wherein the dry gas is carbon
dioxide.
15. The method of claim 10, wherein the dry gas is nitrogen.
16. The method of claim 10, wherein the dry gas is a mixture of
carbon dioxide and of air.
17. The method of claim 10, wherein the dry gas is a mixture of
carbon dioxide and of nitrogen.
18. The method of claim 10, wherein the dry gas is not moved during
operation.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National Stage Entry of International
Patent Application Serial Number PCT/EP2013/002369, filed Aug. 8,
2013, which claims priority to German patent application no. DE
102012016086.0, filed Aug. 14, 2012.
FIELD
The invention relates to a method and a device for introducing
oxygen into a pressurized fluidized bed gasification process which
is typically employed in a gasification reactor according to the
high-pressure Winkler method (HTW method).
BACKGROUND
The HTW method has been known for a long time and is
tried-and-tested technology whereby both particulate and liquid or
pasty carbon-containing fuels are converted into synthesis gas. The
fuels used are also heavy fuels with a very high ash content and
also biomass-based fuels and carbon-containing waste materials.
These are introduced into a fluidized bed, which is operated as a
bubbling fluidized bed, and are gasified by means of oxygen, steam
and CO.sub.2. In contrast to other gasification methods, the HTW
method works at moderate temperatures at which the ash which occurs
does not melt. This has operational benefits particularly in the
case of corrosive ashes.
The addition of oxygen has to be metered very accurately, since
excessive metering would lead to increased burn-out and therefore
to an increase in the CO.sub.2 content in the synthesis gas, which
must be avoided. Also, excessive metering would lead, in the
immediate surroundings of the oxygen inlet points, to a meltdown of
the ash particles, with the result that caking with the fluidized
bed material may occur and would lead in turn to material adhering
to the oxygen lances. Accurate, quick and fine regulation of the
oxygen feed is therefore necessary because the fuels are partly fed
discontinuously under pressure. This leads to especially stringent
requirements to be fulfilled by the oxygen lances which are
typically used for introducing the required oxygen into the
fluidized bed reactor.
Corresponding oxygen lances are described, for example, in DE 34 39
404 C2 and DE 44 07 651 C1 which correspond to the hitherto
existing prior art. In these, the problem of possible caking is
solved in that, at the point of exit of the oxygen, steam addition
is arranged in such a way as to form a steam film which envelops
the emerging oxygen jet. The turbulences generated at the same time
in the emerging gas jet have a very high steam content which
prevents overheating of the entrained fluidized bed particles and
thus considerably reduces the tendency to caking.
However, this technology presents problems at pressures above 8 to
10 bar. Before being added to the oxygen lance, the oxygen is
usually preheated. For safety reasons, however, it would be
preferable not to carry out heating above 180.degree. C., since in
this case equipment parts, in particular seals, which are customary
in the industry are attacked. Above 200.degree. C., there are
statutory licensing restrictions in the use of material. If the
preheated oxygen is introduced into the oxygen lance at 180.degree.
C. and if superheated steam is applied in an enveloping pipe,
condensates are formed at a pressure of above 8 to 10 bar on the
steam side of the oxygen-carrying pipe. These condensates change
the flow conditions of the gas outlet to such a great extent that
an enveloping steam film is no longer formed around the oxygen
lance. This leads to the failure of the oxygen lances.
SUMMARY
The object of the invention is, therefore, to make available a
device and a method for introducing oxygen into a pressurized
fluidized bed gasification process which is also suitable for
operating pressures of above 10 bar and, along with high safety and
availability, is efficient.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure is described in detail below with reference
to the attached drawing figure, wherein:
FIG. 1 is a side cross section view of an embodiment of an oxygen
lance of the present disclosure, the mouth of which is configured
to be directed into the fluidized bed of a HTW gasification
reactor.
FIG. 2 is a schematic diagram depicting an embodiment of a layout
for the supply lines for each of oxygen, carbon dioxide, and steam
to be fed into an oxygen lance of the present disclosure.
DETAILED DESCRIPTION
Disclosed herein is an oxygen lance having at least three pipes
arranged coaxially, one at least partially disposed within in the
other, and at least in each case delimiting an annular gap,
wherein: the outermost pipe being designed for the conduction of
superheated steam and having a steam feed point, the middle pipe
being designed as an annular gap, the innermost pipe being designed
for the conduction of oxygen with a temperature of at most
180.degree. C. and having an oxygen feed point, there being
arranged inside the innermost pipe a temperature probe which
reaches to just short of the mouth of the innermost pipe, the
innermost pipe tapering in a nozzle-like manner upstream of its
mouth, the innermost pipe issuing into the middle pipe, and the
mouth of the middle pipe projecting further in relation to the
mouth of the outermost pipe.
In one refinement, the middle pipe may be designed as a blind pipe
closed on both sides, and in this case the term "mouth" used in the
preceding paragraph is intended in this limiting instance to refer
merely to the pipe end in the vicinity of the mouth of the
outermost pipe. In another refinement, the middle pipe is open on
the mouth side of the oxygen lance. In a further refinement, the
middle pipe is designed for the conduction of dry gas and has a gas
introduction point. In this case, in a further refinement, there
may be provision whereby the middle pipe tapers in a nozzle-like
manner upstream of the mouth of the innermost pipe issuing into the
middle pipe.
Dry gas is understood here, as is customary in combustion
technology in contrast to steam generation technology, to mean an
industrial gas without steam fractions. By contrast, moist gas is
understood below to mean an industrial gas which also contains
steam fractions, although this is not intended to mean that a
multiphase mixture has been formed. Superheated steam is therefore
to be considered as moist gas, even though it is dry in the sense
that wet steam has not occurred.
The object is also achieved, as described above, by means of a
method for introducing oxygen into a fluidized bed gasification
reactor, operated according to the HTW method, by means of an
oxygen lance, moist gas being fed into the outermost pipe at a
pressure above the pressure in the fluidized bed gasification
reactor, oxygen being conducted into the innermost pipe at a
temperature of at most 180.degree. C. and with a pressure above the
pressure in the fluidized bed gasification reactor, moist gas
emerging from the mouth of the outermost pipe as a cladding flow
around the mouth of the middle pipe and the emerging free jet, the
flow velocity of the emerging moist gas being set higher than that
of the emerging gas from the innermost pipe.
In refinements of the method, there may be provision whereby dry
gas is introduced into the middle pipe at a pressure above the
pressure in the fluidized bed gasification reactor, and thereby
oxygen and dry gas are intermixed upstream of the mouth of the
middle pipe.
In further refinements of the method, there is provision whereby
the moist gas is superheated steam or a mixture of carbon dioxide
and of superheated steam.
In further refinements of the method, there is provision whereby
the dry gas is carbon dioxide, nitrogen or a mixture of carbon
dioxide and of air or a mixture of carbon dioxide and of nitrogen.
Moreover, insofar as is desirable in the gasification process,
operation without dry gas is possible, the positive effects upon
the temperature of the moist gas being maintained. The minimum feed
temperature of the dry gas into the middle pipe arises from the dew
point of the moist gas used in the outermost pipe, this
corresponding in the case of pure steam to the saturated steam
temperature.
It became apparent that this technical solution is especially
beneficial economically, since the supply lines for carbon dioxide
can be used due to the need to ensure inertization of the oxygen
lances during rapid shutdowns, and the insertion of a further pipe
into the oxygen lances entails only little outlay. The choice of a
dry gas with high specific heat capacity and the additional
shielding of the hot moist gas against the cooler oxygen prevent an
appreciable lowering of temperature in the steam-carrying outermost
pipe and therefore the condensation of steam in the outermost
pipe.
The invention is explained in more detail below by means of 2
sketches.
FIG. 1 in this case shows diagrammatically a section through an
oxygen lance, the mouth of which issues into the fluidized bed of
an HTW gasification reactor, not shown, and
FIG. 2 shows the circuitry of the supply lines for oxygen, carbon
dioxide and steam.
Oxygen 1 is conducted into the innermost pipe 2 in which the
temperature measuring device 3 is arranged. The temperature amounts
to 180 degrees Celsius and the pressure at the inlet to
approximately 28 bar. The exact pressure is determined by means of
the quantity control which feeds the reactor with exactly the
quantity of oxygen just required instantaneously for gasification.
Carbon dioxide 5 at 230 degrees Celsius is added to the middle pipe
4. Superheated steam 7 with a pressure of approximately 29 bar and
a temperature of 410 degrees Celsius is introduced into the
outermost pipe 6. This steam heats the carbon dioxide to a
temperature of approximately 270 degrees Celsius, the oxygen
likewise being heated slightly. Since the dew point of the steam is
not in this case undershot, steam is not condensed out and no
droplets are formed at the mouth 8 of the outermost pipe, so that a
homogenous steam film can be formed around the tip of the oxygen
lance.
The oxygen of the innermost pipe and the carbon dioxide of the
middle pipe are brought together at the mixing point 9 into a
common gas stream, the feed point already lying inside the
fluidized bed in the HTW gasification reactor. The mixture is
conducted as a free jet 10 into the fluidized bed, the steam film
preventing the oxygen from forming vortices around the nozzle tip
and thus preventing possible local overheating with the result of
ash softening and caking at the nozzle tip. The fluidized bed
reactor can thereby be operated at a pressure of 28 bar.
FIG. 2 shows a circuit diagram with supply lines for oxygen 11,
carbon dioxide 12 and superheated steam 13 and also with the most
important shut-off and regulating valves. In an emergency, carbon
dioxide can be introduced into the oxygen line via the scavenging
valve 14 and into the steam line via the regulating valve 15. As a
rule, the two valves are closed. As a function of the oxygen
quantity required, the regulating valve 16 serves for the oxygen
supply, regulating valve 17 serves for regulating the quantity of
carbon dioxide and the regulating valve 18 serves for the
introduction of steam. Oxygen 11 can also be distributed to other
nozzle levels via the oxygen distributor 19.
The following computing and design examples illustrate the
invention: In example 1, the outermost pipe is subjected to steam
and the middle pipe to nitrogen. In example 2, the outermost pipe
is subjected to steam and the middle pipe to carbon dioxide. In
example 3, the outermost pipe is subjected to a mixture which is
composed in equal proportions by mass of carbon dioxide and of
steam and the middle pipe is subjected to carbon dioxide. In
example 4, the outermost pipe is subjected to steam and the middle
pipe is left without any throughflow.
In all the examples, the innermost pipe is subjected to oxygen, the
inside diameter amounting to approximately 25 mm and a thermocouple
with a thickness of 11 mm being arranged inside. All the
indications of dimension are approximate indications obtained from
design calculations.
TABLE-US-00001 Example 1 Example 2 Example 3 Example 4 gap of the
outermost pipe [mm] 9 15 15 15 gap of the middle pipe [mm] 10 4 4 4
mass throughflow through the outermost 0.039 0.039 0.039 0.039 pipe
[kg/s] mass throughflow through the middle pipe 0.0039 0.0039
0.0039 -- [kg/s] mass throughflow through the innermost 0.225 0.225
0.225 0.225 pipe [kg/s] inlet temperature into the outermost pipe
410 410 410 410 [.degree. C.] inlet temperature into the middle
pipe [.degree. C.] 230 230 230 -- inlet temperature into the
innermost pipe 180 180 180 180 [.degree. C.] outlet temperature
from the outermost pipe 400 390 390 390 [.degree. C.] outlet
temperature from the middle pipe 270 270 270 -- [.degree. C.]
outlet temperature from the innermost pipe 182 182 182 182
[.degree. C.]
In all instances, the saturated steam temperature of the moist gas
of the outermost pipe is at no point undershot in the middle pipe,
and therefore condensation cannot occur.
The invention is not restricted to the examples illustrated, and,
furthermore, it is also possible, in the case of different load
situations or operating situations, to adapt the respective
throughflows to the requirements in a flexible way.
LIST OF REFERENCE SYMBOLS
1 oxygen 2 innermost pipe 3 temperature measuring device 4 middle
pipe 5 carbon dioxide 6 outermost pipe 7 steam 8 mouth of the
outermost pipe 9 mixing point 10 free jet 11 oxygen 12 carbon
dioxide 13 steam 14 scavenging valve 15 regulating valve 16
regulating valve 17 regulating valve 18 regulating valve 19 oxygen
distributor
* * * * *